A Pilot Project to Implement a Pharmacist-Managed Remote Blood Pressure Monitoring Service

Abstract

Background: Clinicians often hesitate to adjust antihypertensive medications based solely on clinic blood pressure (BP) readings. Limitations to obtaining home readings include access to sphygmomanometers and ability to provide accurate, reliable readings upon follow-up. Objective: This study examined whether an online platform linked to remote BP monitoring improved BP management and facilitated effective clinical interventions by pharmacists. Methods: Thirty patients with uncontrolled hypertension were enrolled and provided a remote BP monitor for home use. BP data downloaded to an online platform were monitored by two clinic pharmacists. Daily BP checks were requested (up to twice daily), and pharmacists called patients approximately weekly for 6 months. Through approved protocols, pharmacists individualized interventions to improve patient care. Descriptive statistics were used for demographic and clinical data. Results: The average systolic BP reduction was 39 mmHg (IQR = 17-52.5) for the 21 patients included in analysis. A target BP <140/<90 was achieved by 67%, and 76% had improved BP control. Patients utilized the cuff 2-4 times (n = 10) or >5 times weekly (n = 11). Through 261 patient contact attempts, the pharmacists requested more BP checks (n = 62), changed medications (n = 57), or provided non-pharmacologic counseling (n = 24) most often. Medication changes commonly included dose increases (n = 35) and additional agents (n = 17) for BP control. Spironolactone (n = 5) and thiazide diuretics (n = 5) were the most added medications. Conclusions: Most patients were willing to check their BP when provided with devices. The majority achieved a clinically significant decrease in home BP readings, demonstrating that pharmacist-driven home-monitoring programs can improve the optimization of hypertension regimens.

Keywords

hypertension remote monitoring blood pressure pharmacist-managed

Background

Nearly half of adults in the United States have hypertension, and only 24% of those diagnosed meet blood pressure goals.¹ The American Heart Association and the American Academy of Family Physicians (AAFP) acknowledge inconsistencies between office and home blood pressure readings and cite evidence that home blood pressure monitoring (HBPM) may serve as a more reliable predictor of cardiovascular disease, as well as aid in identifying patients with masked or white coat hypertension.^2,3 Studies have also shown that simply monitoring blood pressure at home does not result in blood pressure reductions but can be effective when combined with other interventions.² Additionally, HBPM is more tolerable than 24-hour ambulatory blood pressure measurement and more reproducible than clinic blood pressure measurement.⁴

Though the benefits of HBPM are starting to be recognized, many barriers to patients performing HBPM exist. The most common barriers to HBPM include: environmental context and resources (such as low reimbursement, cost of equipment to the patient, and time for analyzing data and communicating with patients) and beliefs about capability and consequences (confidence in patients being able to complete HBPM testing, potential for inaccurate results, and non-adherence).⁵

There appears to be a gap in the literature identifying successful and sustainable models for implementing HBPM in primary care. Patients receiving nurse support in conjunction with an online platform had statistically lower systolic blood pressure (SBP) at 12 months than the usual care group with no difference in diastolic blood pressure (DBP), despite significantly more medication changes in the intervention group.⁶ A systematic review and meta-analysis of HBPM studies with varying levels of interventions concluded that combining HBPM with more intensive interventions resulted in statistically significant reductions in SBP, DBP, and the likelihood of a patient having uncontrolled blood pressure at 12 months. These interventions included feedback via phone, feedback and education via phone or web, or patient counseling in person or via telephone.⁷

Evidence exists to support pharmacists’ role in managing patients utilizing HBPM. The Hyperlink Cluster Trial randomized patients to receive usual care or the telemonitoring intervention. Pharmacist intervention significantly increased the percentage of patients with BP at goal compared to usual care.⁸ This study seeks to add to the literature regarding pharmacists’ use of HBPM to improve HTN control and increase use of HBPM in primary care.

Methods

Study Design

This pilot project took place at an urban family medicine clinic on the campus of an academic medical center. The intervention was targeted to 30 patients, who were enrolled after screening by the clinic’s two pharmacists. The pharmacists screened patients being seen in clinic each day for eligibility. Alternatively, physicians could recommend screening of a particular patient for inclusion. Patients were eligible for inclusion if they were at least 18 years old and had a primary care physician at the clinic, had all blood pressure readings above 140 systolic and 90 diastolic for the previous 6 months, and were prescribed at least two antihypertensive medications. Patients were excluded if they were on hospice; undergoing active chemotherapy; had a diagnosis of chronic kidney disease stage 3 or worse; uncontrolled psychiatric disorder; alcohol or substance use disorder (unless in remission for at least 6 months); had a myocardial infarction, stroke, or vascular surgery in the previous 6 months; unstable housing situation; or were pregnant at the time of enrollment. After enrollment, patients were excluded from analysis if they averaged fewer than two BP checks per week. The study was approved by the Institutional Review Board.

If screening criteria were met, the pharmacist discussed enrollment with the patient and obtained consent. Upon enrollment, an account on the monitoring platform was created for each patient and the patient was provided with a sphygmomanometer with a unique identification number that was linked to their account. Each patient was also provided with education about nonpharmacologic treatment for hypertension, blood pressure goals, and proper technique for checking blood pressure, and their medication list was confirmed. Blood pressure was taken on the study sphygmomanometer at the time of enrollment to ensure accuracy compared to clinic reading (checked at the beginning of the visit and at the time of enrollment on the same day), to ensure the patient understood the steps for use, and to verify the reading would be sent to the monitoring platform. Patients were instructed to check their blood pressure at least daily (up to twice daily) and no preferred time was specified.

Intervention

The BodyTrace sphygmomanometer (BodyTrace, Inc., Palo Alto, CA) was an arm cuff that automatically sent readings via cellular connection, along with a time stamp, to an online platform that both the patient and the pharmacists could access at any time. The platform allowed multiple users to enroll under a single clinic so that more than one clinician could access patient readings. Upon login, the platform homepage provided a summary of the most recent blood pressure, previous blood pressure, 7-day average, and change in 7-day average for each patient. Additionally, individual readings could be viewed for each patient under the patient’s profile. Email alerts could be customized so that emails would be sent to both the pharmacists and the patient if the reading was above or below a certain threshold, or if no readings had been recorded within a set timeframe.

Once enrolled, the pharmacists attempted to contact patients via telephone approximately weekly for 6 months to follow-up on blood pressure readings. A collaborative practice agreement was in place to allow the pharmacists to make changes to medication regimens and order labs for monitoring when necessary. The pharmacists also provided targeted nonpharmacologic and adherence counseling with each call, if appropriate. Additionally, if the patient had two readings or fewer for that week, pharmacists would provide counseling on importance of HBPM and having adequate measurements and no therapy changes were made. Interventions were categorized as nonpharmacologic counseling (when no medication changes were made), addition of medication, dose increase, change to another medication, stopping a medication, ordering labs for monitoring, and request for more blood pressure checks. Only one intervention was documented per telephone encounter, though targeted nonpharmacologic counseling was provided along with medication changes.

Study Outcomes and Data Analysis

The primary outcomes of this study were the change in clinic blood pressure reading at study enrollment to 6 months after enrollment, since this is the value most insurers use to assess achievement of blood pressure metrics; change in average weekly home blood pressure, defined as weekly mean from week one of enrollment compared to weekly mean at 6 months (as calculated on the monitoring platform; and percentage of patients achieving target blood pressure. A target blood pressure of <140/<90 was used for all patients in accordance with AAFP recommendations, which are used by prescribers at the study site.⁹ Additionally, this study collected types and quantity of pharmacist interventions. All data were analyzed via descriptive statistics.

Results

Thirty patients were enrolled in the study. Four patients withdrew during the 6-month period (one withdrew consent, three believed their cuffs were inaccurate), two patients were excluded from study continuation due to illicit drug use, and three patients were excluded from BP analysis because they had fewer than 50 BP readings (average of two readings per week) over the intervention period (Figure 1).

Figure 1.

Participants enrolled in the study.

Demographic data are recorded in Table 1. Most patients were black (n = 19) and female (n = 19). The mean number of blood pressure medications prescribed per participant at baseline was 2.95 (SD = 0.72) and the most prescribed classes were thiazide diuretics (n = 16), dihydropyridine calcium channel blockers (n = 15), and angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (n = 14).

Table 1.

Baseline Demographics (n = 21).

Demographic	Value
Male (n, %)	2 (9.5)
Age (n, %)
<40 years	1 (4.8)
40-49 years	5 (23.8)
50-59 years	7 (33.3)
60-69 years	7 (33.3)
70-79 years	1 (4.8)
Race (n, %)
Black	19 (90.5)
White	1 (4.8)
Other	1 (4.8)
Number of antihypertensives (mean, SD)	2.95 (0.72)
2	6
3	10
>3	5
Antihypertensive class (n)
Dihydropyridine calcium channel blocker	15
Thiazide diuretic	16
ACEI/ARB	14
Beta-blocker	9
Non-dihydropyridine calcium channel blocker	2
Hydralazine	4
Spironolactone	2

ACEI, angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor blocker.

Of the 21 patients analyzed, BP decreased in 76% (n = 16), and 67% (n = 14) achieved the target BP of <140/<90. The average reduction in SBP was 39 mmHg (IQR = 17-52.5) and in DBP was 17.5 mmHgm (IQR = 6.5-26.5). Patients utilized the cuff 2-4 times (n = 10) or >5 times weekly (n = 11) on average. Home readings from baseline to the end of the study period using weekly average were 21 mmHg (IQR = 2.5-36) lower for SBP and 10 mmHg (IQR = 4-21) lower for DBP.

A total of 261 attempts at contact were made, 183 (70.1%) of which were successful, and 152 interventions were documented. Thus, 83% of successful contacts resulted in an intervention. The most common intervention was a request for more blood pressure checks (n = 62) or a medication change (n = 57), followed by nonpharmacologic counseling (n = 24) (Table 2). The average number of medication interventions per patient over the 6-month period was 2.71 (SD = 2.03) (range = 0-8).

Table 2.

Interventions (n = 152).

Intervention	N (%)
Request for more BP checks	62 (40.8)
Nonpharmacologic counseling	24 (15.8)
Lab monitoring	9 (5.9)
Medication change	57 (37.5)
Dose increase	35
Change medication	4
Hydrochlorothiazide to hydrochlorothiazide/triamterene	1
Hydrochlorothiazide to chlorthalidone	3
Stop medication (clonidine)	1
Start medication	17
Dihydropyridine calcium channel blocker	3
Thiazide diuretic	5
Spironolactone	5
ACEI/ARB	2
Other	2
Number of antihypertensives at study end (mean)	3.86
2	3
3	4
>3	14
Antihypertensive class at study end (n)
Dihydropyridine calcium channel blocker	18
Thiazide diuretic	21
ACEI/ARB	16
Beta-blocker	10
Non-dihydropyridine calcium channel blocker	2
Hydralazine	5
Spironolactone	7

ACEI, angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor blocker.

Discussion

The results of this pilot study add to the literature demonstrating the effectiveness of HBPM combined with other interventions to improve the control of HTN in primary care settings. The SBP, DBP, and likelihood of patients reaching goal BP were higher in this study at 6 months than seen in other studies at 12 months.⁶ For comparison, in a systematic review of HBPM, mean SBP reduction and mean DBP reduction were 6.1 mmHg and 2.3 mmHg, respectively, in the highest intensity intervention groups.⁷ Also, within this study, the patients in the highest intensity intervention groups were also 56% more likely to reach BP goals than patients not receiving the intervention.⁷ In a study using online, patient-entered HBPM readings and nurses, SBP and DBP decreased by 3.4 mmHg and 0.5 mmHg more, respectively, in the intervention group compared to the usual care group.¹⁰

In a previous study using a similarly designed sphygmomanometer, online platform, and pharmacists as care providers, BP was controlled in 71.8% of intervention patients at 6 months, SBP was decreased by 10.7 mmHg and DBP decreased by 6 mmHg more from baseline than usual care patients at 6 months.⁸ The results of our study compare favorably to these; pharmacist involvement, particularly within the confines of a collaborative practice agreement, in HBPM programs appears to accentuate the benefits compared to other healthcare professionals.

The area where pharmacists most improved clinical inertia in this study was the titration of medication dosages. Additionally, though we did not record baseline comorbidities for data analysis, interventions in this study indicate that pharmacists contributed to use of guideline-recommended therapy. This is evidenced by the number of participants who had thiazide diuretics or dihydropyridine calcium channel blockers added to their regimens, in our primarily black study sample.

The study outcomes would likely not have been as pronounced or positive without a collaborative practice agreement. The benefits of these agreements have been well-documented in many chronic disease states, including hypertension.^11–13 In this clinic setting, there would undoubtedly have been delays in medication changes and improvement in blood pressure readings as pharmacist recommendations waited for physician and resident physician review and approval. This could also have led to lack of adherence to the new regimen, as patients may have forgotten the changes if delayed or may have refilled previous doses of medications while waiting.

The goal of this pilot study was to determine plausibility of rolling this study out to a larger population. Based on pharmacist experience and patient outcomes, there are several key items to consider. Anecdotally, thirty patients being reviewed and called weekly, in addition to the pharmacist’s regular responsibilities, was a heavy load for one pharmacist full-time equivalent. The addition of another pharmacist or ancillary personnel, such as pharmacy students, technicians, and residents, would be helpful if a larger population was included, though students and technicians would have to be supervised by a pharmacist in order to utilize the collaborative practice agreement.

Another key factor impacting the efficacy of this intervention was patient engagement. The majority of telephone encounters were to encourage more consistent blood pressure measurements and several calls resulted in voicemail. Not surprisingly, there was a correlation between the number of blood pressure checks and a decrease in blood pressure. Having physicians identify patients who were motivated to engage in the service as they presented to clinic may have been more effective than enrolling based on chart review. Once identified, pharmacists performed in-person training for enrolled patients, which may have increased patient willingness to make medication changes since they were more familiar with the caller and were not receiving cold calls. If the patient has a longitudinal relationship with his or her physician, a warm handoff may also lead to better patient engagement. Since we did not follow these patients beyond 6 months, it is unknown whether blood pressures remained controlled once patients went back to usual care. It is expected that physicians continued to follow each patient and monitor and adjust therapy as needed; however, it is unknown if this occurred. Maintaining goal blood pressure is essential in the prevention of long-term complications, such as renal and cardiac effects and thus long-term control would be important to consider in implementation of this intervention in the future.

While this study could not overcome all of the barriers identified in other studies and previously mentioned, it did address several. To minimize access issues, patients were provided the cuff at no cost to them, regardless of insurance status. Patients were also thoroughly trained on how to accurately measure BP, which helped with provider confidence in the accuracy of readings. The weekly follow-up calls helped with non-adherence since patients received consistent reminders. These attempts to overcome barriers may have contributed to improvements in the readings.

There are limitations to this study and its generalizability. First, as a pilot study, the number of participants in the study was small. In addition to the limited study sample size, the relatively short follow-up time makes it difficult to evaluate the impact of a pharmacist-led HBPM program on cardiovascular outcomes. Secondly, though pharmacists intended weekly contact with all patients, this was not always possible as other clinical responsibilities had to be balanced. Thirdly, the online platform used to house HBPM readings was not integrated into the study site’s electronic health record, leading to increased documentation time for the pharmacists as they had to switch between systems. Also, the study site was only reimbursed for the sphygmomanometer, not the clinic service. Though a portion of clinic reimbursement is tied to the percent of total patients who met the goal of <140/<90, the financial sustainability of such a service will need to be evaluated by any site considering such a program, as there was a lack of direct reimbursement for these services at the time of the study. Possible direct reimbursement strategies might include use of chronic care management codes or home blood pressure monitoring (99 473). Another limitation is that the pharmacists relied on patient-reported adherence data collected at each phone call. It is possible that patient adherence may not have matched, but this study did not use any method of fill confirmation. Lastly, the BP goal of <140/<90 used in this study is more conservative than that recommended by the American College of Cardiology and American Heart Association.² If a lower goal had been set, the outcomes may have been different, both in the number of patients achieving goal BP and in the number of medications required.

Conclusion

The results of this study reinforce the impact that pharmacists have on improving control of blood pressure in patients using HBPM. Additionally, these results demonstrate that a pharmacist-driven HBPM program can reduce clinical inertia and improve the optimization and monitoring of HTN medication regimens. The workload of the pharmacist as well as reimbursement for the service should be explored further before a larger population is included.

Footnotes

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iDs

Kaci Boehmer

Chris Johnson

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